2545417721 has 16 divisors (see below), whose sum is σ = 3194539008. Its totient is φ = 1970298000.

The previous prime is 2545417717. The next prime is 2545417729. The reversal of 2545417721 is 1277145452.

It is a happy number.

It is not a de Polignac number, because 2545417721 - 2² = 2545417717 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2545417729) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 97835 + ... + 121088.

It is an arithmetic number, because the mean of its divisors is an integer number (199658688).

Almost surely, 2^2545417721 is an apocalyptic number.

It is an amenable number.

2545417721 is a deficient number, since it is larger than the sum of its proper divisors (649121287).

2545417721 is a wasteful number, since it uses less digits than its factorization.

2545417721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 219092.

The product of its digits is 78400, while the sum is 38.

The square root of 2545417721 is about 50452.1329677943. The cubic root of 2545417721 is about 1365.3783779317.

It can be divided in two parts, 254541 and 7721, that added together give a palindrome (262262).

The spelling of 2545417721 in words is "two billion, five hundred forty-five million, four hundred seventeen thousand, seven hundred twenty-one".